Ptors And Related Cytokines Expressed In The Cecal Intraepithelial Lymphocytes Of Chickens Infected With Eimeria Tenella

In order to fight off pathogen infection, host invariably activates the innate and adaptive immune responses. As the first line of host defense, inborn immunity is firstly mediated by pattern recognition receptors (PRRs) distributed in host’s cells and tissues that recognize conserved microbial structures often referred as pathogen-associated molecular patterns (PAMPs). NOD-like receptors (NLRs) are a novel kind of PRRs, which play important roles in linking innate and adaptive immunity. Up to date, however, little known about the roles of chicken NLRs in the immunoreaction and/or immunomodulation against pathogen invasion. In this paper, we preliminarily investigated the roles of Chicken NLRs against Eimeria tenella infection.Cecal intraepithelial lymphocytes (IELs), components of gut-associated lymphoid tissue (GALT) which immediately release cytokines and cause killing of infected target cells when encountering antigens, could be as the first effector of opposing Eimeria tenella invasion and parasitism. Here, the dynamic profiling of NOD-like receptors’and their associated cytokines’gene transcription levels in cecal IELs were evaluated by quantitative RT-PCR method when the one-day-old and21-day-old chickens were challenged with1×104E.tenella sporulated oocysts. The specific primers for NOD-like receptors NLRC1, NLRC3, NLRC5, NLRP3coding ORFs and associated cytokines IFN-α, IFN-β, IFN-y, TNF-a, IL-6, IL-1β, IL-12, NF-kB p65, NF-KBp68c-rel, NF-kB rel_B genes were designed, and their transcription fluctuations were detected in the IELs collected from the chicken cecum at the3、6、12、24、48、72hours post-infection (hpi).The results showed that, in 21-day-old chickens, the expression levels of NLRC1, NLRC3, NLRC5, and NLRP3were all up-regulated, and reach to their peak values at72hpi. The detected cytokines also concurrently shown the similar dynamic states except for the IFN-a and IL-1β. By contrast, NLRs gene transcription levels had relative weak dynamic changes in one-day-old challenged chickens, only NLRC5had one peak value at72hpi. Transcription levels of cytokines like IFN-a, IFN-β, IFN-y, IL-1β and IL-12were up to highest value when3hpi in one-day-old infected chickens,and then decreased significantly. The transcription levels of TNF-a in21-day old chickens were always higher than those in one-day aged chickens, suggesting its potentially important roles against E. tenella infection.Our preliminary results revealed the impacts of NOD-like receptors and related cytokines on the anti-coccida in chickens, and will help to understand the immune mechanisms of anti-infection in early stage of Eimeria invasion in chicken.